WO2017207088A1

WO2017207088A1 - Method and device for drying fibres wetted with glue that are provided for producing fibreboards

Info

Publication number: WO2017207088A1
Application number: PCT/EP2017/000578
Authority: WO
Inventors: Fritz Schneider
Original assignee: Fritz Schneider
Priority date: 2016-05-28
Filing date: 2017-05-12
Publication date: 2017-12-07
Also published as: DE102016006499B3

Abstract

The invention relates to a method and device for drying fibres that are provided for producing fibreboards and have previously been wetted with glue in the dry state. The fibres wetted with glue are sucked axially through a vertically extending fibre dryer from below by means of transportation air. The fibre dryer is a vertically oriented drying tower (21) and the fibres are sucked through substantially along the entire length thereof. The transportation air flows through annular gaps (25) into the drying tower. The annular gaps are arranged one above another in a casing (26) of the drying tower and are assigned to hot-air supply chambers (24) in groups of adjacent annular gaps. The hot-air supply chambers (24) are arranged along the length of the drying tower (21) and feed differently settable quantities of hot air per unit time to the drying tower (21) over the height thereof.

Description

DESCRIPTION

Process and apparatus for drying glue-wetted fibers for making fiberboard

The invention relates to a method for drying fibers previously wetted with glue for the production of fibreboards, according to the preamble of claim 1. Furthermore, the invention relates to a corresponding apparatus according to the preamble of claim 11. The fibers are preferably made of lignocellulosic material. and / or cellulosic materials. The fiberboards are light, medium density or high density plates.

It is customary to glue fibers which are intended for the production of MDF or HDF boards in the wet state. However, a so-called blow-I-Beleimung has disadvantages. These are described, for example, in WO 02/14038. The disadvantages of the Blow-Iine gluing can be avoided by gluing the fibers in a dry state. Dry gluing devices which are similar to one another are described in the publications DE 10247412 A1, DE 10247413 A1, DE 10247414 A1. In WO 2012/153205 A1, a device and a method for dry gluing are described in which a stream of loose wood material is shaped into a hollow stream by means of a deflector and glue is sprayed onto an inner surface of the hollow stream by ring-shaped gluing nozzles. DE 02006040044 B3 discloses a method and a device for dry-lining fibers, wherein the fibers are glued into two partial fiber streams and the partial streams are subsequently combined to form a fiber stream.

The mentioned known devices or the known method are all based on the principle of producing large-area high-speed flight fiber streams which are sprayed with glue on their surface become. Unfortunately, serious disadvantages have been found in practice in these processes. The predominantly very fine glue droplets of less than 20 micrometers are entrained by the fast and high-fiber flow and penetrate only insufficiently into the flow.

Due to their fineness they quickly reach gas speed. This entrainment effect causes them to have little relative speed to the fibers. The consequences are that a significant proportion of the glue droplets do not come into contact with any fiber and remain isolated. The isolated glue droplets are removed from the process after the separation of fiber and air with the air. This not only leads to glue losses and therefore adversely affects the efficiency of the gluing, but another problem is that the non-fibered glue droplets get caught on inner wall surfaces of the apparatus, resulting in massive

Pollution leads. According to DE 10247412 A1, DE 10247413 A1, DE 10247414 A1, it is therefore possible to provide in one for gluing

used chute to generate a shell air stream, which serves to prevent caking on the walls of the chute. The same is also provided in a method and a plant for fiber sizing according to DE 102004001527 A1.

Although measures such as the use of dried fiber material, as described in DE 102004054162 B3, have largely eliminated the problem of contamination on walls of a transport device for the freshly glued fibers, but at the same time the investment and operating costs for the dry gluing in the air driven.

A generic method and a generic device are known from DE 102006024895 A1. However, hot air partial streams that pass through the annular gaps in the drying tower, fixed in their intensity relative to each other.

The invention is therefore based on the object, a generic

Process for drying freshly glued fibers in the dry state To provide, in which contact of the fibers wetted with glue with an inner wall of the fiber dryer used is largely prevented and a desired flow profile can be adjusted in the drying tower. It is a further object of the invention to provide an associated apparatus for drying such fibers.

The object concerning the method is solved by the features of claim 1. The fibers, after they have been dry-glued, from the bottom axially through a vertically erected drying tower over its entire or substantially entire length or height

through which air is used to transport the fibers through the drying tower. The drying tower has a round, preferably circular, or polygonal cross-section. The transport air is warm air. This warm air flows through annular gaps, which are arranged one above the other in a shell of the drying tower and are referred to below as annular gaps, in the drying tower. The guided through the annular gaps in the drying tower air - hereinafter also referred to as clearance air - effectively ensures that the fibers that are freshly glued and thus have a cold tack, do not come into contact with an inner wall of the drying tower. Contact of the fibers with the inner wall of the drying tower is thus largely prevented. The air supplied through the annular gaps can thus also be referred to as barrier air. Preferably, the annular gaps extend over the full circumference of the drying tower shell. They can be formed by slats in the manner of a blind.

The preferred inlet temperature of the hot air into the drying tower is oriented to the desired temperature which the glue-wetted fibers should have at the exit of the drying tower. The preferred temperature is 40 ° C to 50 ° C. Pre-heated fibers shorten the pressing time and thus increase the performance of the press. The drying tower has hot air supply chambers, which are arranged over the length of the tower and designed to supply the drying tower over its height amounts of hot air, which may be different. Each hot air supply chamber is a group of adjacent ones

Assigned to annular columns. The number of annular gaps per hot air supply chamber may be different.

By optionally different amounts of hot air are supplied to the drying tower through the different hot air supply chambers, a desired flow profile can be set in the drying tower.

Furthermore, by means of the hot air supply chambers, the different amounts of hot air to be introduced per unit time over the height of the tower can be adjusted so that a visual effect is produced. Thus, it can be achieved that unwanted coarse material reaches only a small height in the drying tower, because in a lower region of the tower per unit time supplied transport air volume or the speed of the transport air are relatively low, and the coarse material then from a stream of transport air in the The tower falls out and sinks to a floor area of the drying tower where it can be removed automatically or manually. It can be provided, for example, that the amount of hot air supplied per unit of time through each hot air supply chamber increases the transport air speed by 0.5 to 2 meters per second, preferably 1 meter per second. In particular, it may be provided that the transport air velocity in the region of the lowermost warm air supply chamber is approximately 3 meters per second and increases by approximately 1 meter per second in the region of each arranged above hot air supply chamber, due to a corresponding hot air supply through the respective chamber. Coarse material generally sinks at a transport air speed of approximately 6 meters per second or less, while fibers are transported upwards at a transport air speed of approximately 6 meters per second. With In other words, the transport air velocity in a lower

Area of the drying tower about the air velocity in one

Hobby correspond. It can be provided that the hot air supply chambers associated with a common pressure fan for supplying hot air and between the pressure fan and each hot air supply chamber each at least one air inlet valve is arranged, which serves to set the respective amount of hot air per unit time for each hot air supply chamber.

Preferably, the annular gaps have a substantial vertical alignment component. As a result, the hot air supplied through an annular gap first flows along a respective section of an inner wall of the drying tower before it enters the main transport air flow, which moves along a central longitudinal axis of the drying tower. This section may for example have a length of 30 to 50 cm. In this way, it can be effectively achieved that contact of the fibers wetted with glue with an inner wall of the drying tower is largely prevented.

A contact of the fibers wetted with glue with an inner wall of the drying tower can be prevented in a particularly effective manner by preferably adjusting the quantities of warm air supplied per unit of time by the hot air supply chambers such that the warm air emerging from each of the annular gaps has a higher flow velocity than the air in the main transport air flow. Preferably, the velocity of the air emerging from all the annular gaps is at least a factor of two higher.

Preferably, the lining of the fibers takes place in a base region of the drying tower. In this case, there is no transport device

required to guide the glued fibers into the drying tower. In order to Consequently, the problem is circumvented that such a transport device could be contaminated by the still existing cold stickiness of the fresh glue. With regard to such a gluing process, it may be provided that the fibers are fed from a fiber metering device to a transport device and the transport device has at least two pressure lines, which are referred to below as "fiber pressure lines." In these fiber pressure lines, at least one fan, which is arranged between a discharge of the fiber metering device and a respective outlet opening of the fiber-pressure lines,

generates pneumatic pressure. Preferably, such a fiber pressure line fan is provided for each fiber pressure line. By means of the fiber pressure lines, the fibers are transported to at least one glue misting nozzle. The fibers are at least partially guided in two separate partial fiber streams and exit in the form of two partial streams from the outlet openings of the fiber-pressure lines. The from the two

Outlet openings of the fiber-pressure lines exiting fiber partial flows are arranged such that they meet and unite into a fiber stream. Preferably, the distance between the fibers of the combined fiber stream and the inner wall of the drying tower at the beginning of the fiber stream is at least one meter. For example, if the inside diameter of a circular drying tower is 4 meters, the distance between the two edges of the combined fiber stream and the tower inner wall at the origin of the fiber stream may be 1 to 1.5 meters, for example.

Between the exit of the fiber sub-streams from the fiber-pressure lines and the merging into a fiber stream, the fibers are glued by means of the at least one glue-atomizing nozzle. The glue misting nozzle generates a stream of glue mist consisting of glue droplets. The size-misting nozzle is directed to the inner surfaces of the sub-streams and located centrally of an area in which the fiber sub-streams unite and in the direction of the glue ejection spaced from the area of unification of the fiber sub-streams. The glue misting nozzle is blocked by air in The direction of the glue outlet flows around. The fibers of the combined fiber stream are sucked through the drying tower.

The outlet openings of the fiber-pressure lines have the shape of a

Half ring, wherein the edges of the two half rings adjoin. In this way, the two outlet openings form the shape of a

closed ring. Preferably, the ring is circular. Then, the two outlet openings form a circular gap, which is separated symmetrically to its center by the radially aligned, adjacent walls of the outlet openings. The respective gap preferably has a relatively small width, compared to the outer or inner circumference of the ring. The exiting fiber sub-streams then have a relatively small thickness, i. they are then flat except for their curvature. It can be provided in particular that the two fiber-pressure lines in an area in front of the outlet openings together resemble the shape of a tube having an outer and an inner wall, wherein the fibers are guided in the cavity between these two walls and in the region both outlet openings, the walls and thus the cavity are curved radially inwardly, in order to give the exiting fibers the desired exit direction in this way. The air flowing around the at least one glue misting nozzle is compressed air, which is generated by means of a fan. This compressed air transports the glue mist, which already emerges from the glue misting nozzle as a glue mist stream, in addition in the direction of the fibers emerging from the fiber pressure lines. In the following, this compressed air is referred to as Leimnebeltransportluft.

By being generated by means of a fan other than the at least one fiber pressure line fan, the fibers and the glue droplets, when they meet one another

Relative speed to each other.

Furthermore, a relative velocity also results from the different directions of movement of the fibers on the one hand and the glue droplets on the other hand. between the fibers to be glued and the impinging glue droplets. Characterized in that the at least one glue atomizing nozzle is arranged centrally relative to the region of the union of the fiber sub-streams and the fibers usually have a higher kinetic energy due to their greater mass compared to the glue droplets, even if their

Speed is lower than that of the glue droplets, it is additionally ensured that the fibers to be glued, which move radially from the outside inwards to the glue mist stream, penetrate into this. Thus, the

It is very likely that fibers and glue droplets will combine due to a collision so that no glue droplets remain isolated, as is the case with the prior art described above.

The fibers flowing radially inwards from the outside into the glue mist stream effectively prevents glue mist from penetrating the fiber sub-streams and entering an air space which adjoins the outer surfaces of the fiber sub-streams. Because the fiber sub-streams drive the glue droplets in the region of the union of the two partial fiber streams, ie in the center of the two moving toward each other partial streams. The at least one glue misting nozzle may in particular be a multi-fluid nozzle, i. an air, gas, or steam atomizing nozzle, or even a single-fluid nozzle, i. a pressure atomizing nozzle, act. When using more than one glue atomizing nozzle, a mixture of the above-mentioned glue nozzle types can also be provided. In such a case, the pressure atomizing nozzles operate to maintain the same glue droplet size with a constant rate of sizing performance, whereas the air, gas or vapor atomizing nozzles vary in size of the sizing to match the production conditions found in the prior art

Production output can fluctuate.

When supplying different amounts of hot air in the drying tower by means of the hot air supply chambers for setting a

desired flow profile in the tower can be taken into account that the The fibers wetted with glue in the drying tower are initially at a certain distance due to the momentum they have when emerging from the fiber pressure lines and the momentum transferred by the glue mist flow

Move the drying tower upwards before transport has to be supported by the warm transport air from the hot air supply chambers. This means that in a lower region of the drying tower, where the combined fiber stream has its origin, significantly less from the

Warm air supply chambers supplied hot air is required as in an upper region of the drying tower.

The speed of the glue mist transport air can preferably be set independently of the speed of the fibers emerging from the fiber pressure lines by a speed of the associated fan being variable and / or an air inlet valve with which the amount of glue mist transport air per unit of time and thus also the flow rate

Speed of the glue mist transport air is set. In this way it is ensured that the required relative speed between the glue droplets and the fibers to be glued or also the required difference in the kinetic energy can be set. In this way, the glue droplets and the fibers to be glued can be given the necessary impulse, so that when they collide with one another, they fuse together securely.

Furthermore, it is preferably provided that the speed of the fibers emerging from the fiber pressure lines can be adjusted by the speed of the at least one fan of the fiber pressure lines being variable or adjustable. If both the speed of the glue mist transport air and the speed of the fibers emerging from the fiber pressure lines are adjustable, the relative speed between glue droplets and fibers can be adjusted particularly well.

The at least one glue misting nozzle is disposed in the base portion of the drying tower so as to apply glue on top of the Output fiber partial currents. For this purpose, the starting point of the Leimnebelstromes be arranged below the outlet openings of the fiber-pressure lines. There is then sufficient clearance between the starting point of the glue mist stream and the fibers to be glued so that the glue mist stream can propagate sufficiently conical before colliding with the fibers. In particular, it can be provided that the closed ring formed by the two outlet openings is circular, ie both an outer and an inner circumference of the ring, which delimit the outlet openings, are each circular. Preferably, the glue mist stream is circular in cross-section and lies completely within the inner circumference of the ring. The glue mist stream runs through the center of the ring. In this way, a high symmetry is achieved, which ensures a particularly uniform

Gluing the fibers provides. Alternatively, a plurality of glue atomizing nozzles may also be provided in the base region of the drying tower, which are arranged in a ring shape. In this case, a hollow Leimnebelstrom resulting in

Sprührichtung something expands. Again, it is preferably provided that the outlet openings result in a circular closed ring. The arrangement of the glue atomizing nozzles should then also be circular, so that the glue mist flow in cross-section is substantially in the form of a ring with a circular inner and a circular outer

Has diameter and runs within the ring of the outlet openings symmetrically to the center or center. In this case it can be provided that the fibers are glued only in a portion of the path between the outlet openings of the fiber-pressure lines and the region of the union.

Preferably, the streams are surrounded by their exit from the fiber pressure lines to the region of the union over their respective entire outer surface of an air flow adjacent to this surface. This centering air flow serves to limit the fiber sub-streams in their thickness, by ensuring that the fiber sub-streams in radial Direction, based on the glue spray direction, can not expand. Further, the centering air flow serves to trap glue mist which may have passed through the fiber sub-streams and guide it into the combined fiber stream. This avoids that glue droplets remain isolated and settle on the inner wall of the drying tower. Thus, internal contamination of the drying tower are largely avoided.

Preferably, the speed of the Zentrierluftstromes can be adjusted by the speed of a fan which provides the Zentrierluftstrom with a desired pressure, is variable and / or an air inlet valve is provided with which the amount of Zentrierluftstroms per unit time can be influenced. For the glue mist transport air and the Zentrierluftstrom the same fan can be provided. But also possible are separate fans. The speed setting can

preferably independent of the speed of emerging from the fiber pressure lines fibers.

In the production of MDF boards, depending on the process, between 10 and 15% return material, ie fiber material, is returned to the process. It is essentially the permanent accumulation material of the fiber mat longitudinal saw and the sporadic tipping material when the gluing process is interrupted due to a malfunction. Because this material is old and over-dried, it is added to the process with special facilities only in small quantities. According to the invention, such material can ideally be returned to the production process of glued fibers via the centering air flow. On the one hand, a good mixing of the recirculated with the fresh material can be achieved, and on the other hand also a good reconditioning in the drying tower.

Preferably, the outlet openings of the fiber-pressure lines are directed to the glue mist flow, that the angle between the flow direction of Glue mist transport air and the fibers to be glued is 45 to 90 degrees, more preferred is an angle of 60 to 80 degrees. An angle of more than 90 degrees, so negative to the flow direction of Leimnebeltrahsportluft, is conceivable. When said angle is less than 90 degrees and the exit ports of the fiber delivery lines form a circular ring, the two partial fiber streams together form substantially the shape together between exit from the fiber delivery lines and a region where they combine a hollow cone. The centering air flow described above then covers the entire outer surface of the hollow cone shape.

The above object is with respect to the device by the

Characteristics of claim 11 solved. The method can be carried out with the device. The drying device has a vertical

erected drying tower on. This is designed so that the glue-wetted fibers from below axially through the drying tower by means of

Transport air to be sucked through, what about the whole or in the

Essentially entire length or height of the drying tower happens. In particular, it can be provided for a fan. The drying tower has a round, preferably circular, or polygonal cross-section. As an inlet for the transport air, the drying tower has annular gaps which are arranged one above the other in a jacket of the drying tower. Preferably, they extend over the full circumference of the drying tower shell. The transport air is warm air. With regard to the features of the drying device, reference is also made to the corresponding statements in connection with the method according to the invention, wherein the features described in connection with the method also apply correspondingly to the device and this also applies vice versa. The device has the same advantages as previously described in connection with the method. This also applies to the features described below and preferred embodiments of the device. The drying tower has hot air supply chambers, which are arranged over its length and designed to supply the drying tower over its height amounts of hot air, which may be different. Each hot air supply chamber is a group of adjacent annular gaps

assigned. The number of annular gaps per hot air supply chamber may be different.

It can be provided that the drying tower also fulfills the function of a classifier. For this purpose, it is provided that by means of the hot air supply chambers, the different amounts of hot air to be introduced per unit of time over the height of the tower are adjusted so that a visual effect is produced. So can be achieved that unwanted coarse material is transported only up to a small height in the drying tower, because there the per unit time supplied transport air volume is relatively low, and that the coarse material then falls out of a stream of transport air and into a

Floor area of the drying tower drops, where it can be removed automatically or manually, for example by means of cleaning flaps. The air velocity in a lower region of the drying tower can thus correspond approximately to the air velocity in a hover sight.

The hot air supply chambers may be associated with a common pressure fan for supplying hot air. In each case an air inlet valve can be arranged between the pressure fan and each hot air supply chamber, which serves to set the respective amount of hot air per unit time for each hot air supply chamber.

Preferably, the annular gaps have a substantial vertical alignment component. This ensures that each supplied through the annular gap warm air initially flows along a respective section of an inner wall of the drying tower before it enters a main transport air stream, which is fed from the air supplied through the annular gap transport air and moves along a central longitudinal axis of the drying tower. In this way it can be achieved particularly effectively that a contact of the With glue wetted fibers with an inner wall of the drying tower is largely prevented.

For the purpose of the preceding gluing of the fibers to be dried, it may be provided that the device has at least one fiber-metering device for fibers, and furthermore a transport device which serves to transport fibers discharged from the fiber-metering device to gluing means. The transport device has at least two pressure lines, in which pneumatic pressure is generated by means of a fan. This is referred to below as a fiber-pressure line fan. It is arranged between a discharge of the fiber metering device and a respective outlet opening of the fiber pressure lines. At least two fiber pressure lines are provided, at least over a certain distance, in which separate partial fiber streams are guided. Two partial fiber streams emerge at outlet openings of the fiber-pressure lines as partial flow in such a way that the two partial streams meet one another and form a fiber stream

unite. For this purpose, the outlet openings are aligned accordingly. The sizing agents comprise at least one sizing nebulizer nozzle disposed in a base region of the drying tower and serving to generate a stream of sizing mist, the sizing mist consisting of glue droplets. The at least one size fog nozzle is disposed within an air duct and directed toward the inner surfaces of the fiber sub-streams between exit from the fiber pressure lines and merging into a fiber stream. This air line is associated with a fan for generating an air flow. The at least one glue atomizing nozzle is arranged centrally with respect to a region of the union of the fiber sub-streams and spaced apart in the spraying direction from this region.

The outlet openings of the fiber-pressure lines have the shape of a

Half ring, wherein the edges of the two half rings adjoin. On In this way, the two outlet openings form the shape of a closed ring having an outer and an inner wall, the fibers emerging between these two walls. Preferably, the ring or the two walls are circular. In this case, the two outlet openings form a circular gap which is symmetrical to its

Center is separated by the radially aligned, adjacent walls of the outlet openings. The outlet openings are preferably designed so that the curved partial flows are flat, i. have a relatively small thickness compared to their extension along the curve. The air duct, in which the at least one glue atomizing nozzle is arranged, is a compressed air line. It leads by means of the fan pressurized air, which additionally transported the glue mist, which already exits the Leimvernebelungsdüse as Leimnebelstrom. The compressed air line is therefore referred to below as Leimnebeltransportluft line. Of the

Leimnebelstrom has substantially a round cross-section.

According to the invention, an outer circumference of the glue mist stream lies within the closed ring formed by the outlet openings of the fiber pressure lines or within the inner circumference of the ring. This is accomplished by annularizing the glue mist transport air conduit and spacing the glue atomizing nozzle to the area of unification of the fiber sub-streams and adjusting the glue fog transport air surrounding the glue mist stream accordingly. By the drying tower through the different hot air supply chambers each different amounts of hot air can be supplied, a desired flow profile can be set in the drying tower, as above in connection with the inventive method

is described.

Preferably, the speed of the glue mist transport air can be adjusted independently of the speed of the fibers emerging from the fiber pressure lines in that a speed of the associated Can be changed fan and / or an air inlet valve, with which the amount of Leimnebeltransportluft per unit time and thus the

Speed of the glue mist transport air is set. Preferably, the at least one glue atomizing nozzle is height adjustable, so that their distance from the outlet openings of the fiber pressure lines is variable. This distance affects the rate at which the glue mist stream strikes the fibers of the fiber sub-streams. Because the

Glue droplets rapidly lose their velocity as soon as they leave the glue misting nozzle. Due to the mentioned possibility of a distance adjustment can additionally on the speed of

Leimtröpfchen be impacted on their impact on the fibers, so in an optimal way, the relative speed between the

Leimtröpfchen and to be glued fibers are adjusted.

Furthermore, it is preferably provided that the speed of the fibers emerging from the fiber pressure lines can be adjusted by the speed of the at least one fiber pressure line fan being variable or adjustable. This is preferably possible regardless of the setting of the speed of the glue mist transport air. If both the

The speed of the Leimnebeltransportluft and the speed of the fibers emerging from the fiber pressure lines can be adjusted, the relative speed between glue droplets and fibers can be adjusted particularly well.

The at least one size fog nozzle is arranged to deliver glue up to the fiber sub-streams. For this purpose, the starting point of the Leimnebelstromes be arranged below the outlet openings of the fiber-pressure lines. There is then sufficient clearance between the starting point of the glue mist stream and the fibers to be glued so that the glue mist stream can propagate sufficiently conical before colliding with the fibers. In particular, it can be provided that the closed ring formed by the two outlet openings is circular, ie both a outer as well as an inner circumference limiting the outlet openings of the ring is in each case circular. Preferably, the glue atomizing nozzle is designed so that the glue mist stream is circular in cross section, the glue mist stream passing through the center of the ring. In this way, a high symmetry is achieved, which ensures a particularly uniform gluing of the fibers.

Alternatively, several Leirhvernebelungsdüsen be provided, which are arranged in a ring. In this case, results in a hollow

Leimnebelstrom, which expands somewhat in the direction of spraying. Again, it is preferably provided that the outlet openings result in a circular closed ring. The arrangement of the glue atomization nozzles should then also be circular, so that the glue mist stream is essentially annular in cross-section with a circular inner and a

is circular outer diameter and runs symmetrically to the center or the center of the center. In this case, the fibers are glued only in a portion of the distance between the outlet openings of the fiber pressure lines and the region of the union. Preferably, the outlet openings of the fiber-pressure lines are surrounded by an adjacent annular outlet opening of a compressed-air line. This outlet opening is preferably divided in the middle, so that the

annular outlet opening composed of two semi-annular outlet openings. The compressed air line is designed to eject a designated as Zentrierluftstrom air flow, the fiber sub-streams up to the

Surrounds their union area over their entire outer surface and adjacent to these outer surfaces. The purpose and advantages of this centering airflow are described above in the context of the method. Preferably, the speed of the Zentrierluftstromes can be adjusted by the speed of a fan, which provides the Zentrierluft- stream with a desired pressure, is variable and / or an air inlet valve is provided, with which the amount of Zentrierluftstroms per Time unit can be influenced. For the glue mist transport air and the Zentrierluftstrom the same fan can be provided. But also possible are separate fans. The at least one glue misting nozzle and the glue mist transporting air can in particular be aligned vertically. Preferably, the

Outlet openings of the fiber-pressure lines directed to the Leimnebelstrom so that the angle between the flow direction of the Leimnebeltransportluft and the fibers to be glued is 45 to 90 degrees. Particularly favorable for this angle is a range of 60 to 80 degrees. An angle of more than 90 degrees, that is negative to the flow direction of the Leimnebeltransportluft is conceivable. When said angle is less than 90 degrees and the exit ports of the fiber discharge lines form a circular ring, the two partial fiber streams together form substantially the shape of a hollow cone between the exit from the fiber delivery lines and the region where they unite , The centering air flow described above then covers the entire outer surface of the hollow cone shape.

If the gluing means and the drying tower form one unit as described above, as explained in connection with the method, the problem arises that an otherwise required transport means could be contaminated by glue.

The invention will be described below with reference to three exemplary embodiments, reference being made to the figures. Show it:

Fig. 1 shows schematically a Beleimungs- and

2, a portion A of the Beleimungs- and shown in Fig. 1

Drying device in which the actual gluing process takes place, with some features shown in Fig. 2 in Fig. 1 for reasons of

reduced display size are not shown, 2a shows a somewhat different embodiment of the gluing means and thus a variant of the partial area A according to FIG. 2, FIG. 3 shows a cross section through the partial area A along the section line III-III in FIG.

4 shows a further embodiment of the gluing means and thus an alternative to the partial area A according to FIG. 2, FIG.

Fig. 5a shows the portion B of the gluing and shown in Fig. 1

Drying device, namely a drying tower of the device,

5b is a plan view of a detail of Fig. 5a,

FIG. 6 shows a lower section of the drying tower shown in more detail in comparison with FIG. 1, but in contrast to FIG

Beleimungsmittel shown in FIG. 2a are shown. In the figures, the same features are designated by the same reference numerals. The gluing and drying apparatus according to FIG. 1 has a fiber-dosing device 2 filled with fibers 1, from which the fibers 1 of a

Transport device to be supplied. The transport device has at least two pressure lines 3 and 3a (see FIG. 2). In these

Pressure lines 3 and 3a is constructed by at least one fan, which is arranged between a discharge 4 of the Faserdosiereinrichtung 2 and respective outlet openings 5 and 5a of the pressure lines 3 and 3a, pneumatic pressure. In the case of the embodiment of the gluing and drying device according to the invention described here-advantageously-one such fiber-pressure line ventilator 6 and 6a is provided for each pressure line 3 and 3a. By means of the pressure lines 3 and 3a, the fibers 1 are transported to a round glue mist stream 7, which in the following

Leimnebelrundstrom is called. In this case, the fibers 1 at least partially guided in two separate fiber streams and occur in the form of two partial fiber streams 8 and 8a from the outlet openings 5 and 5a of the pressure lines 3 and 3a. The two end regions of the pressure lines 3 and 3a are hereinafter referred to collectively as the fiber nozzle 9. The pressure lines 3 and 3a have at least in sections a rectangular cross-section, which is formed before the outlet openings 5 and 5a to a semi-annular cross-section of 180 °, so that emerge from the two outlet openings 5 and 5a two Faserhalbring- streams 11 and 11a, which together closed fiber ring stream form (see Fig. 3). The rectangular cross-section of the pressure lines 3 and 3a causes a homogeneous with respect to the flow cross-section

Fiber distribution. The fiber nozzle 9 represents a cross-sectional reduction of the pressure lines 3 and 3a.

A glue misting nozzle 10 is within a compressed air line 12 which is circular in cross-section and somewhat in an upper region 12a

funnel-shaped expands, arranged. The nozzle 10 generates a stream of glue mist, which is also formed into the glue mist stream 7 by the action of pressurized air flowing through the compressed air line 12 and transposing the glue mist. Therefore, in the following, the air in the compressed air line 12 is referred to as Leimnebeltransportluft and the line 12 as Leimnebeltransportluft line. Several glue misting nozzles 10 could also be provided.

The Leimnebeltransportluft flows in cross-section annularly the Leimnebel from below its mouth from the Leimvernebelungsdüse 10 in its flow direction. The annular air flow of the Leimnebeltransportluft ensures that the Leimnebelrundstrom 7 is smaller in diameter than the inner diameter of the above closed fiber ring stream when leaving the outlet openings 5 and 5a of the pressure lines 3 and 3a.

As a result, there is a radial distance between the Leimnebelrundstrom 7 and the outlet openings 5 and 5a of the pressure lines 3 and 3a, as shown in particular in FIG. 3 can be seen.

The Leimnebelrundstrom 7, whose starting point is below the outlet openings 5 and 5a, flows in a vertical direction from bottom to top through the center of the closed fiber ring current. The outlet openings 5 and 5a of the pressure lines 3 and 3a are directed to the Leimnebelrundstrom 7, that the fibers 1 impinge on the Leimnebelrundstrom 7 at an angle of approximately 45 ° to the flow direction. An angle of incidence of more than 90 °, that is negative to the flow direction of the Leimnebelrundstroms 7, would also be conceivable. In particular, the

Incident angle also be 60 ° to 80 °.

The glue misting nozzle 10 is an air-gas steam atomizing nozzle. It is connected to an glue pump 19 and has a connection 20 for compressed air, gas or steam. The glue misting nozzle 10 could alternatively be a single-fluid nozzle. If more than one glue atomizing nozzle 10 is used, a mixture of the above-mentioned glue nozzle types may also be provided.

Adjacent to the fiber nozzle 9 is a centering compressed air line 15, which is designed to carry pressurized air, which is referred to below as centering air. As can be seen in Fig. 3, the centering compressed air line 15 through a partition wall 15 b is continuously separated to an optimum flow of the

To obtain centering air. The centering air exits at two outlet openings 15a and 15c, which are adjacent to the outlet openings 5 and 5a of the fiber pressure lines 3 and 3a.

The fiber pressure line fans 6 and 6a of the pressure lines 3 and 3a for the fibers 1 and a fan 13 (not shown in Fig. 1) for the

Leimnebeltransportluft and the centering air can be adjusted in their capacity or performance by themselves by a corresponding control of their drive change their rotational frequency. In addition, the amount of centering air flowing per unit time in the centering compressed air line 15, by means of two air inlet valves 17 and 17a and the amount of Leimnebeltransportluft flowing per unit time in the Leimnebeltransportluft line 12, set by means of an air inlet valve 18 independently. In this way, the airspeed of the fibers 1 emerging from the fiber nozzle 9 and the flying speed of the glue droplets of the glue mist stream 7 can be adjusted independently of each other to a value which gives the fibers 1 and the glue droplets the necessary momentum to collide with each other to securely connect with each other. In addition, the intensity of the centering air can be adjusted by means of the air inlet valves 17 and 17a.

Due to the higher mass due to their greater mass usually higher kinetic energy of the fibers 1 with respect to the fine glue droplets ensures that the fibers 1 penetrate into the Leimnebelrundstrom 7. Since the glue droplets meet within the cone-like Leimrundstromes 7 and the fibers 1 at an angle of about 45 ° to 90 °, a relative speed is given to each other alone by the different direction of movement. In addition, but also in terms of amount

different speed of glue droplets and fibers to be glued. The flying speed of the fibers 1 can be adjusted so that the fibers 1 penetrate the glue mist flow stream 7, if desired, into its center or overshoot the center of the glue fog flow stream 7. In the latter case, a countercurrent occurs in which the fibers wetted with glue cross and mix. In addition, this leads to a high fiber concentration, in which the probability is very high that fibers and glue droplets find and none

Glue droplets remain isolated.

By radially inwardly flowing from the outside inward fibers 1 is effectively avoided or even completely prevented that glue mist, by the fiber flow in the center of the total glue / fibers is driven into an air space 14 outside a unified fiber stream 16 passes. This combined fiber stream 16 is formed by the combined fiber sub-streams 8 and 8a. The fibers of the fiber stream 16 are wetted with glue.

The centering fulfills two tasks, namely a restriction of the radial extent of the fiber stream 16 and a collection of glue mist, which has escaped from the gluing zone in the air space 14, and its return to the combined fiber stream 16. The latter contributes to internal soiling of the Device are largely avoided.

As described above, recycling material can ideally be returned to the process via the air transport path of the centering air. Advantages are good mixing and reconditioning in a drying tower 21 described below.

It could be provided that one or more further fiber nozzles are attached above the fiber nozzle 9 in the same pattern. In this case, a centering compressed air line would be arranged between the first and second fiber nozzle in the flow direction of the glue mist flow.

The embodiment of the gluing means according to FIG. 2 a differs from the embodiment according to FIG. 2 in particular in that the

Centering air line 15 is not directly adjacent to the fiber nozzle 9. Rather, there is a distance between these two as shown in FIG. 2a. This allows the centering air to strike the partial fiber streams 8, 8a at an angle. This may be advantageous in terms of preventing glue droplets from entering the air space 14. In a middle area, in which also projections of the drying tower shell 26 can be seen, the gluing means are shown in a lateral plan view, while they are shown above in sectional view and below in a schematic view. In particular, the transition from a rectangular cross section to the circular cross section of the fiber pressure lines 3, 3a and the centering compressed air line 15 can be seen. As an alternative to the embodiments according to FIGS. 2 and 2 a, the glue mist circular flow may also be designed such that, as in the embodiment of the gluing and drying device according to the invention shown in FIG. 4, it is hollow in the interior and it is an im cross-section

annular Leimnebelrundstrom 7a is. In this case, the

Glueing and drying device several glue atomizing nozzles 10, which are arranged in a ring. In the three embodiments of the gluing means according to FIGS. 2, 2 a and 4, a centrifugal force acts on the fibers 1 due to the curvature of the fiber pressure lines 3, 3 a, so that the fibers 1 become the respective ones

External surface of the fiber sub-streams 8, 8a compress. This makes it less likely that glue droplets completely penetrate the fiber sub-stream and reach the centering air. In addition, the latter is also counteracted by the fact that the fibers 1 entrain the glue droplets in the direction of the region in which both partial fiber streams 8, 8a unite. Both effects are not shown in FIGS. 2, 2a and 4. As shown in Fig. 1, the fibers 16 discharged from the fiber nozzle 9 and provided with glue open from below axially into the above-mentioned drying tower 21. This is vertically erected and may for example have a height of 30 to 40 meters. The glue-provided fibers 16 are sucked by at least one suction fan 32, which is arranged on the output side of the drying tower 21 after an air separator 33, and transported through the drying tower 21. The for the

Transport of the provided with glue fibers 16 necessary transport air is supplied to the drying tower 21 as warm air. For this purpose, air is sucked in from the atmosphere by means of suction means 22 and heated by means of a heat exchanger. The hot air has a temperature of 40 ° C to 90 ° C. The

preferred temperature of the hot air entering the drying tower 21 is 80 ° C (see above). The hot air flows out of five hot air supply chambers 24

Ring column 25 in a drying tower shell 26 in the drying tower 21. The intake fan 32 is so adjustable in its performance that in the drying tower 21 always there is a negative pressure. The annular gaps 25 each extend radially over the full circumference of the drying tower shell 26. It can over the entire length of the drying tower shell 26 such

Ring gaps 25 may be arranged, but it seems possible that in an upper region (see Fig. 1) and in a lower region of the drying tower 21 no annular gaps 25 are required. The number of annular gaps 25 per hot air supply chamber 24 may be different, typically five to eight annular gaps per hot air supply chamber could be provided. An annular gap 25 may, for example, have a height of 40 to 50 cm. As can be seen in FIG. 5 a, the annular gaps 25 are delimited by fins 40, which form the wall of the drying tower 21. The fins 40 are connected to a mounting tube 36 by means of a pipe clamp 37 and a

Attached connector 38. So that the lamellae 40 have the desired distance from each other, spacers 39 are provided, which are arranged on the attachment tube 36 between in each case two adjacent clamps 37. Fig. 5b shows a separate plan view of the upper, in Fig. 5a over its height completely shown blade 40 (without the blade arranged underneath) and their attachment to the mounting tube 36. The individual hot air supply chambers 24 per unit time

supplied hot air quantities can be different. The amount of hot air supplied to the individual hot air supply chambers 24 per unit time is adjusted to the needs required for transport of the sized fibers 16 in the drying tower 21 and / or required for an ideal airfoil in the drying tower 21. It can also be achieved by a sufficient flow of air gap 28, which is passed through in each case an annular gap 25 in the drying tower 21 (see Fig. 5a), and a sufficient speed of this gap air 28 can be achieved that a Inner wall 27 of the drying tower 21 does not come into contact with the freshly glued fibers 16.

The individual hot air supply chambers 24 are supplied with hot air by a common pressure fan 29 and on both sides of the drying tower 21 arranged air lines 29a. The hot air supply chambers 24 have a positive pneumatic pressure. The drying tower 21 has a negative pressure. The hot air quantities of the individual hot air supply chambers 24 per unit time are set via two respective air inlet valves 30. The air inlet valves 30 are arranged on both sides of the drying tower 21 in each case at an air inlet 31 into the hot air supply chamber 24 in order to obtain the most symmetrical flow profile in the drying tower 2. However, only one of the air ducts 29a, only one of the air inlet valves 30 and only one of the air inlets 31 is shown in FIG. 1, in contrast to the embodiment of the gluing and drying apparatus according to the invention shown in FIG.

As shown in FIG. 6, but not shown in FIG. 1, the drying tower 21 has a viewing window 41 and an access door 42 in the drying tower shell 26 at the level of the gluing means for inspecting the gluing means. The fins 40 are shown in Fig. 6 only for the second hot air supply chamber 24 seen from below.

As a result of the fact that the fibers 16 have experienced an increase in their speed and thus their momentum through the fiber nozzle 9 due to the reduction in cross section, and an impulse has been transmitted to the fibers 16 by the glue misting nozzle 10, the glued fibers 16 in the drying tower 21 move a distance far before their transport must be supported by hot air from the hot air supply chambers 24. This means that in a lower area of the drying tower significantly less

Warm air from the hot air supply chambers 24 is required as in an upper region of the drying tower 21st The primary function of the drying tower 21 is the post-drying of the fibers, which have already been dried by a fiber dryer (not shown), before being fed into the fiber metering device 2, and are then wetted fresh with glue. Fiber dryers are used as single-stage or two-stage dryers, with the second drying stage being comparable in its drying capacity to the drying tower 21. Thus, the drying tower 21, which is part of the dry gluing, also has the function of the second fiber drying stage. Accordingly, according to the invention, it is provided that the fiber concentration in the stream of hot air which transports the sized fibers 16 through the drying tower 21 is at a low level.

A secondary function of the drying tower 21 consists in a

Separation of coarse material, which can be present in the pulp and is sporadic. For this purpose, in the lower area of the

Drying tower 21 the average air speed kept relatively low and corresponds approximately to the air velocity in a Schwebe- sifter. Unwanted coarse particles thus fall out of gravity due to gravity

Air flow out and sink to the bottom of the drying tower 21. There they can be removed automatically or manually, for example by means of cleaning flaps (not shown). By the supply of hot air via the hot air supply chambers 24 in the drying tower 21 in a controlled amount per unit time can be made, there is the possibility to adapt the visual effect in the drying tower to the needs.

The total of passing through the drying tower air may be about three quarters to hot air supplied through the annular gap 25, and to about a quarter of the air required in connection with the gluing, so Leimnebeltransportluft, from the fiber pressure lines 3, 3a exiting Air and centering air together.

The glued from the drying tower 21, glued fibers are fed to the air separator 33. Since it is high-energy hot air, is For economic reasons, it makes sense to return the separated air to the aforementioned fiber dryer (not shown) located in front of the fiber dosing device which would otherwise draw its air from the atmosphere. The separated air simultaneously removes the evaporated water from the gluing system. About 15% of the air exiting from the air separator 33 is returned to the Faserdosiereinrichtung 2 and serve as transport air for the fibers 1. The exact adjustment of this amount of air is regulated via an air inlet valve 34. At a lower outlet of the air separator 33, the fibers 16 provided with glue are transferred via a rotary valve 35 to the further process.

LIST OF REFERENCE NUMBERS

1 fibers

2 fiber dosing device

3 fiber pressure line

3a fiber pressure line

4 discharge of 2

5 outlet opening of 3

5a outlet opening of 3a

6 fiber pressure line fan

6a fiber pressure line fan

7 glue mist circulating stream

7a Leimnebelrundstrom

8 fiber partial flow

8a partial fiber flow

9 fiber nozzle

10 glue misting nozzle

11 fiber half-ring stream

11a fiber half ring stream

12 glue mist transport air line

12a upper area of 12

13 fans

14 airspace 15 Centering compressed air line 15a Outlet opening of 15

15b partition of 15

15c outlet opening of 15

16 combined fiber stream

17 air intake valve

17a air intake valve

18 air intake valve

19 glue pump

20 Connection for compressed air, gas or steam

21 drying tower

22 intake

23 heat exchangers

24 hot air supply chamber

25 annular gap

26 Drying jacket

27 inner wall

28 split air

29 pressure fan

29a air line

30 air intake valve

31 air intake

32 fans

33 air separator

34 air intake valve

35 rotary valve

36 mounting tube

37 pipe clamp

38 connector

39 spacer

40 lamella

41 viewing window

42 access door

Claims

EXPECTATIONS

1. Process for drying fibers intended for the production of fiberboard, which have previously been wetted with glue in the dry state,

wherein the fibers (16) wetted with glue are sucked axially from below through a vertical fiber dryer using transport air,

where the transport air is warm air,

wherein the fiber dryer is a vertically erected drying tower (21) and the fibers (16) are sucked through essentially over its entire length,

the warm air passing through annular gaps (25).

Drying tower (21) flows,

wherein the annular gaps (25) in a jacket (26) of the

Drying tower (21) are arranged one above the other,

characterized in that the annular columns (25) are assigned to warm air supply chambers (24) in groups of adjacent annular columns (25), the warm air supply chambers (24) being arranged over the length of the drying tower (21) and the

Drying tower (21) can be adjusted to different heights

Supply quantities of warm air per unit of time.

2. Method according to claim 1,

characterized in that the quantities of warm air are adjusted so that the speed distribution of the transport air over the length of the drying tower (21) leads to the separation of coarse material, in that the coarse material falls out of a main stream of transport air due to gravity and into a bottom area of the drying tower (21) sinks.

3. Method according to claim 1 or 2,

characterized in that the warm air supply chambers (24) are supplied with warm air by means of a common pressure fan (29) and between the pressure fan (29) and each

At least one air inlet valve (30) is arranged in each warm air supply chamber (24), which serves to adjust the amount of warm air per unit of time, which is passed through the warm air supply chamber (24).

Drying storm (21) should be fed.

4. Method according to one of the preceding claims,

characterized in that the annular gaps (25) each have a significant vertical alignment component, so that the warm air supplied through one of the annular gaps (25) initially flows along a respective section of an inner wall (27) of the drying tower (21) and thereby contact between the fibers (16) wetted with glue and the inner wall (27) is prevented.

5. Method according to one of the preceding claims, characterized in that the fibers (1) are wetted with glue in a base area of the drying tower (21).

6. Method according to claim 5,

characterized in that the fibers (1) of at least one

Fiber metering device (2) through a transport device with at least two fiber pressure lines (3,3a), in which through at least one

Fan (6.6a) generates pneumatic pressure, so that the fibers are transported in two separate fiber sub-streams (8.8a).

exit openings (5.5a) of the fiber pressure lines (3.3a),

that the at least one fiber pressure line fan (6,6a) is arranged between an outlet (4) of the at least one fiber metering device (2) and one of the outlet openings (5,5a) of the fiber pressure lines (3,3a),

that the fibers (1) emerge from the fiber pressure lines (3,3a) as a partial fiber stream (8,8a) in such a way that the two partial fiber streams (8,8a) meet and combine to form a fiber stream (16),

that the outlet openings (5.5a) of the fiber pressure lines (3.3a) are semi-ring-shaped and so on the edges of the semi-ring shape

adjoin one another so that the outlet openings (5,5a) together form the shape of a closed ring,

that the fibers (1) are glued with at least one

Glue misting nozzle (10), which generates a stream (7; 7a) of glue mist consisting of glue droplets and which is applied to the inner surfaces of the Fiber partial streams (8.8a) are directed between the exit from the fiber pressure lines (3.3a) and the combining to form the fiber stream (16) and which are centered in relation to an area of the combination of the fiber partial streams (8.8a) and in the ejection direction of the Glue mist spaced apart

is arranged,

that the glue mist stream (7; 7a) essentially has a round cross section,

that air (12) flows around the at least one glue misting nozzle (0) in the direction of the glue outlet by means of a fan (13).

and that the air (12) flowing around the glue misting nozzle (10) serves to transport the glue mist and flows around the glue mist stream (7; 7a) in a ring shape in such a way that an outer circumference of the

Glue mist stream (7; 7a) lies within the ring formed by the outlet openings (5.5a).

7. Method according to claim 6,

characterized in that a starting point of the glue mist stream (7) lies below the outlet openings (5.5a) of the fiber pressure lines (3.3a), with an outer and an inner circumference of the

The outlet openings (5,5a) of the ring are circular and the glue mist stream (7) is circular in cross section and runs through the center of the ring.

8. Method according to claim 6, characterized in that several, arranged in a ring

Glue misting nozzles (10) dispense glue onto the partial fiber streams (8, 8a), a starting point of which is therefore annular in cross section

Glue mist stream (7a) lies below the outlet openings (5.5a) of the fiber pressure lines (3.3a), an outer and an inner circumference of the ring formed by the outlet openings (5.5a) being circular and the glue mist stream (7a) in Cross section is ring-shaped with a circular inner and outer diameter and is symmetrical to the center of the ring.

9. Method according to one of claims 6 to 8,

characterized in that the partial fiber streams (8,8a) from the exit from the fiber pressure lines (3,3a) until they merge over their entire outer surface from an area adjacent to this surface

Centering air flow (15) are surrounded.

10. Method according to one of claims 6 to 9,

characterized in that the angle between the flow direction of the glue mist transport air (12) and the fibers (1) to be glued is 45 to 90 degrees, preferably 60 to 80 degrees.

11. Device for drying for the production of fiberboard

intended fibers that have been wetted with glue when dry,

comprising a vertically extending fiber dryer and means (32) for sucking through the fibers (16) wetted with glue using transport air through the fiber dryer, whereby the transport air is warm air,

wherein the fiber dryer is a vertically erected drying tower (21) and the means for sucking through are designed to suck the fibers (16) from below axially essentially over the entire length of the drying tower,

wherein the drying tower (21) has annular gaps (25) as an inlet for the transport air,

wherein the annular gaps (25) in a jacket (26) of the

Drying tower (21) are arranged one above the other,

characterized in that the annular columns (25) are assigned to warm air supply chambers (24) in groups of adjacent annular columns (25), the warm air supply chambers (24) being arranged and designed over the length of the drying tower (21), the drying tower (21) to supply different amounts of transport air over its height.

12. Device according to claim 11,

characterized in that between a warm air source (23) and the warm air supply chambers (24) there is a common pressure fan (29) for supplying the chambers (24) with warm air, with each chamber (24) located between the pressure fan (29). there is at least one air inlet valve (30) which is used to adjust the through the respective chamber (24) serves the amount of warm air to be supplied to the drying tower (21) per unit of time.

13. Device according to claim 11 or 12,

characterized in that the annular gaps (25) each have a significant vertical alignment component, so that the warm air (28) supplied through one of the annular gaps (25) initially flows along a respective section of an inner wall (27) of the drying tower (21). flows in order to prevent the fibers wetted with glue from coming into contact with the inner wall (27).

14. Device according to one of claims 11 to 13, characterized in that it further comprises

at least one fiber metering device (2) and

a transport device which is used for the pneumatic transport of the fibers (1) discharged from the at least one fiber metering device (2) to the gluing means (10) and at least two fiber pressure lines

(3,3a), which are designed so that the fibers (1) emerge in two separate fiber partial streams (8,8a) from outlet openings (5,5a) of the fiber pressure lines (3,3a),

to generate the pneumatic pressure, at least one fan (6,6a) between an outlet (4) of the at least one

Fiber metering device (2) and one of the outlet openings (5.5a) of the fiber pressure lines (3.3a) are arranged, wherein the outlet openings (5,5a) of the fiber pressure lines (3,3a) are designed so that the two partial fiber streams each exit as a partial fiber stream (8,8a), and are aligned with regard to their ejection direction so that the two partial fiber streams (8, 8a) meet and combine to form a fiber stream (16),

wherein the outlet openings (5,5a) of the fiber pressure lines (3,3a) are semi-ring-shaped and so on the edges of the semi-ring shape

adjoin one another so that the outlet openings (5,5a) together form a closed ring,

wherein the gluing means have at least one glue misting nozzle (10), which is arranged in a base region of the drying tower (21) and is used to generate a stream (7; 7a) of glue mist consisting of glue droplets and which is applied to the inner surfaces of the partial fiber streams (8, 8a) is directed between the exit from the fiber pressure lines (3,3a) and the combining to form a fiber stream (16) and which is arranged centrally and spaced apart in the glue mist discharge direction in relation to an area of the union of the partial streams (8,8a) and the is arranged within an air line (12),

wherein the at least one glue mist nozzle (10) is designed such that the glue mist stream (7; 7a) generated has a substantially round cross section,

wherein the air line (12) having the glue misting nozzle (10) is assigned a fan (13) to generate an air flow and the air flowing through this air line (12) is used to transport the glue mist and wherein this glue mist transport air line (12) is ring-shaped in cross section, the glue mist nozzle (10) is arranged at a distance from the area of combination of the partial fiber streams (8, 8a) and the glue mist transport air surrounding the glue mist stream (7; 7a) can be adjusted in this way that an outer circumference of the generated glue mist stream (7; 7a) lies within the ring formed by the outlet openings (5.5a).

15. Device according to claim 14,

characterized in that the at least one glue misting nozzle (10) is designed to direct glue upwards onto the partial fiber streams (8,8a)

dispense, with the glue misting nozzle (10) below the

Outlet openings (5.5a) of the fiber pressure lines (3.3a) are arranged, an outer and an inner circumference of the ring formed by the outlet openings (5.5a) being circular and the

Glue misting nozzle (10) is designed so that the generated

Glue mist stream (7) is circular in cross section and runs through the center of the ring.

16. Device according to claim 14,

characterized in that a plurality of glue misting nozzles (10) are arranged and designed in a ring below the outlet openings (5.5a) of the fiber pressure lines (3.3a), glue upwards onto the

To deliver partial fiber streams (8,8a), an outer and an inner circumference of the ring formed by the outlet openings (5,5a) being circular and the glue misting nozzles (10) being designed in such a way that the glue mist stream (7a) generated is annular with a circular cross section inner and outer diameter and is symmetrical to the center of the ring.

17. Device according to one of claims 14 to 16,

characterized in that the outlet openings (5,5a) of the fiber pressure lines (3,3a) are surrounded by an adjacent annular outlet opening (15a, 15c) of a centering compressed air line (15), which is designed to expel a centering air stream which Fiber partial streams (8,8a) from emerging from the fiber pressure lines (3,3a) to their union surround each other over their entire outer surface adjacent to this surface.

18. Device according to one of claims 14 to 17,

characterized in that the at least one glue mist nozzle (10) and the glue mist transport air line (12) are aligned vertically and the outlet openings (5.5a) of the fiber pressure lines (3.3a) are aligned so that the angle between the flow direction of the Glue mist transport air and the fibers to be glued are 45 to 90 degrees, preferably 60 to 80 degrees.